Help! Vacuum leak pump

[all redv]

Vacuum leak or no air from dash vents. Not sure when it started I did find some critter dropping in the car that critter is long gone, I did check vacuum line best I could without really pulling thing apart yet, Very Very nice article on vacuum leak testing. From my understanding the vacuum pump with switch on should come on a few second then turn off if no leak, If there is a leak it may recycle a few time, What my pump is doing with hose attach or disconnect at the first coupling just pass water reserve tank that pump will run for about 3 second and never come back on unless i turn the key off then by to on position, should i replace pump before i pull plenum to see if that little critter bit into a line